Shales admired nothing so much as ambition, but he also managed the feat of having high standards about lowbrow things.“How-word Co-sell — you heard the bell and you came out talking.”The television critic Tom Shales began his 1978 essay with a pitch-perfect impression of his subject, capturing the melodrama, punchy cadence and flamboyant volubility of the most famous sportscaster of his era. He goes on to mock Howard Cosell’s hyperbole and penchant for mistakes while still convincing you of his specific greatness as a television virtuoso. In criticism as nuanced as it is satirical, Shales described the musical quality of Cosell’s voice as “virtually visual,” transforming the crowd of an arena into “a manageable, living room form.”In an argument that could be made today about Stephen A. Smith, the critic locates precisely how a broadcaster became the main event.When people ask what critics inspired me to become one, I tend to mention Pauline Kael and Kenneth Tynan. It’s honest, though not as much as a critic should be. They are prestigious names, celebrated ones who championed legendary artists. But the first critic I ever loved reading was Tom Shales, who began his collection of essays “On the Air!“ by proclaiming his affection for McDonald’s, the smell of Right Guard deodorant and television.Shales, who died last week, had one of the most impressive careers of any cultural journalist of his lifetime. Along with co-writing (with James Andrew Miller) “Live From New York,” the oral history of “Saturday Night Live,” an essential part of the bookcase for anyone who cares about pop culture, he turned The Washington Post, a newspaper best known for its political coverage, into the home of the most influential voice on television of the 1980s and ’90s.Arriving right before the golden age for the medium, he dominated his beat, not just winning a Pulitzer Prize but also doing it while pumping out hundreds of stories a year of a startling range, covering “60 Minutes” with as much insight as he had into Rodney Dangerfield. He was as gifted doing the deadline work of capturing the horror of the space shuttle Challenger explosion as he was at teasing out startlingly candid interviews with careful stars like Johnny Carson and Steve Martin.Shales did not condescend to his thumbs-up-or-down responsibilities. You knew where he stood. He understood that part of the job was to be engaging, and his writing crackled with wit — it was scathing, conversational, sometimes unfair but never dishonest. And yet, his greatest legacy is how he championed television when that was a lonely pursuit.When Shales started his career in the late 1970s, a critic treating television seriously was unusual and refreshing. The “idiot box” was considered a wasteland if not a scourge. Shales didn’t dismiss these critiques. He engaged with them. He admired nothing so much as ambition but also managed the feat of having high standards about lowbrow things.The subtext of so much of his early writing was an argument for the potential of television as art, comfort, cure for loneliness, creator of meaning. He made these points explicitly but also implicitly, in the way he wrote, say, a fascinating 1987 essay about the growing visual ambition of the medium. He didn’t cite only Michael Mann’s direction of “Miami Vice” but also the gonzo monkey cams from “Late Night With David Letterman” and the rise of MTV. “I feel grateful not only that I’m alive in the age of television but that unlike a lot of people I know, I can still find it on occasion, marvelous,” he wrote. “I can be delighted and astonished and exhilarated by it, and appalled.”Shales clearly saw these reactions coming from the same place. His vicious pan of the sitcom “Gimme a Break!” (Sample line: “If I thought television could get substantially worse than this, I am not sure I would have the courage or desire ever to turn the set on again”) emerged from the same place as a rave of Jean Stapleton’s Edith Bunker: He had not only a sense that this stuff does matter but also an impatience with artists and viewers and especially executives who didn’t act like it.This is a valuable quality in a critic. Besides reflecting high standards, it is dramatic. Shales made whatever he wrote about seem to have stakes, even if it was “Family Feud.” And that in turn made you care about game show hosts and comics and news anchors in a way you didn’t before, even if he panned them.When critics die, people tend to point to the things they got right or wrong, as if that were the measure. It isn’t, though a case on that count could be made for Shales. He championed “Cheers,” “Twin Peaks,” “The Sopranos.” He applied critical rigor to comedy specials when there weren’t many, and he understood early that whatever you think about “Full House,” it works.Unlike Kael or Tynan, Shales wasn’t at his best beating the drum for or against something. All his work maintained a skeptical, knowing, light comic style. He always had more passion for the form than for any artist in it. This could lead to brutal honesty. He annually mocked Kathie Lee Gifford’s holiday special with sadistic glee, and while I would like to defend his famous pan of “Late Night With Conan O’Brien” (which even the talk show host admitted decades later was accurate), its dismissive harshness blinds him to the peculiar ambition the green host displayed. (He eventually changed his mind and wrote a rave about O’Brien years later.)Brutal negative criticism is now out of fashion, but it’s too much a part of the human experience to be killed off. It just migrated online. Less casual cruelty is a good thing, but there are real risks to this new politeness. A critic is a kind of reporter, one whose beat requires pacing between mind and gut, filing dispatches filtered through an intellectual apparatus. Once you stop reporting what is there, you cease being useful. Shales never did.When I was growing up in Washington D.C., I didn’t realize my luck that the most influential criticism on late night television was being done in my local paper. Shales loved David Letterman and that surely rubbed off on me. I never met Shales, but when I thanked him for reviewing my biography of David Letterman, he was kind enough to regale me with some war stories, and this advice: “Try not to let The Times suffocate you.”Critics rarely end their careers well. Perhaps this will be of some solace to wounded artists. Shales felt he was pushed out at The Washington Post — he told me (plausibly) that he was a victim of the “cyber apocalypse.” But I didn’t find his message to be bitter, or at least not only that.Criticism is among other things an act of vulnerability. Regularly putting your views out into the world to be picked apart, doing the intrepid thinking, fast writing and enemy-making that is a part of the job while holding onto your sensitivity, curiosity and confidence — it’s harder than it looks. Sometimes you fail or, worse, cut corners. But what I took Tom Shales to mean, in his advice to me, was that the thing you must protect, what requires expending courage on, is your own voice. It’s good advice, worth passing on. More